Optical imaging lens, scanning display device and near-eye display device

Abstract

The embodiment of the application discloses an optical imaging lens, a scanning display device and a near-eye display device, and relates to the technical field of scanning display. The optical imaging lens can slow down aberration generated by the lens, achieve the purpose of correcting various aberrations, and realize clear imaging of an image surface on the basis of improving a field of view by reasonably optimizing the focal length and surface structure of relevant lenses in eight coaxial lenses of the optical imaging lens. The optical imaging lens is combined with a spherical lens and a non-spherical lens, and a single lens and a cemented lens are reasonably used, and the radial maximum effective half aperture of part of the lenses is associated with proportional limitation, so that the large field of view of the optical imaging lens is further ensured, correction of various optical aberrations is strengthened, meanwhile, the volume and weight of the optical imaging lens are further reduced, the overall structure of the optical imaging lens can be more compact, and the production demand of miniaturization of the lens product is met.

Description

Technical Field

[0001] This application relates to the field of scanning display technology, specifically to an optical imaging lens assembly, a scanning display device, and a near-eye display device. Background Technology

[0002] Scanning display imaging, as an emerging display technology, can be used in various application scenarios such as projection display and near-eye display.

[0003] However, existing scanning display imaging systems suffer from drawbacks such as high manufacturing difficulty, high mass production cost, poor imaging quality, small field of view, and inability to achieve miniaturization. These drawbacks limit the market promotion and application of scanning display imaging technology. In particular, when applied to near-eye display scenarios, the limitations of imaging effect and field of view prevent it from meeting the high-resolution performance requirements of near-eye displays, thus hindering the development of near-eye displays into the consumer market. Summary of the Invention

[0004] The purpose of this application is to provide an optical imaging lens assembly, a scanning display device, and a near-eye display device to meet the requirements of a large field of view, high imaging quality, and miniaturized mass production in near-eye display scenarios.

[0005] This application provides an optical imaging lens assembly, which includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged coaxially from a first side to a second side, wherein the focal lengths of the first lens, the second lens, the third lens, and the sixth lens are negative, positive, positive, and positive, respectively.

[0006] The first lens and the optical imaging lens group have the following relationship: 0.7 ≤ |f1 / f 总 |≤1.2, where f1 is the focal length of the first lens, and f 总 The total focal length of the optical imaging lens group is given.

[0007] Further optionally, in a preferred embodiment of the present invention, the first lens, the second lens, the third lens, the fourth lens, the sixth lens, and the eighth lens are all spherical lenses;

[0008] Both the fifth lens and the seventh lens are aspherical lenses.

[0009] Further optionally, in a preferred embodiment of the present invention, both the fourth lens and the sixth lens are cemented spherical lenses.

[0010] Further optionally, in a preferred embodiment of the present invention, both the fourth lens and the sixth lens include two sub-lenses, wherein the two sub-lenses of the fourth lens are arranged along the optical axis from the first side to the second side and their corresponding focal lengths are positive and negative, respectively; the two sub-lenses of the sixth lens are arranged along the optical axis from the first side to the second side and their corresponding focal lengths are negative and positive, respectively.

[0011] Further optionally, in a preferred embodiment of the present invention, the second side surface of the fourth lens near the sub-lens of the fifth lens is concave; the first side surface of the fifth lens is concave.

[0012] Further optionally, in a preferred embodiment of the present invention, the focal lengths of the fourth lens, the fifth lens, the seventh lens, and the eighth lens are negative, positive, positive, and positive, respectively;

[0013] The sub-lens of the fourth lens closest to the fifth lens has the following relationship with the optical imaging lens group: 0.8 ≤ |f 4-2 / f 总 |≤1.5, where f 4-2 The focal length of the sub-lens of the fourth lens closest to the fifth lens, f 总 The total focal length of the optical imaging lens group is given.

[0014] Further optionally, in a preferred embodiment of the present invention, the maximum effective half-aperture of the third lens along the radial direction is Y1, the maximum effective half-aperture of the two opposite surfaces of the fourth lens and the fifth lens along the radial direction is the same and both are Y2, and the maximum effective half-aperture of the seventh lens along the radial direction is Y3.

[0015] Wherein, Y1 and Y2 have the following relationship: 1≤Y1 / Y2≤1.4;

[0016] The following relationship exists between Y2 and Y3: 1.4 ≤ Y3 / Y2 ≤ 1.7.

[0017] This application embodiment also provides a scanning display device, which includes a fiber optic scanner and the aforementioned optical imaging lens group. The fiber optic scanner is used to scan and emit light of an image to be displayed, and the optical imaging lens group is used to magnify and project the scanning surface corresponding to the light emitted by the fiber optic scanner.

[0018] The fiber optic scanner includes an actuator and an optical fiber fixed to the actuator. The portion of the optical fiber extending beyond the actuator forms an optical fiber cantilever, which performs two-dimensional scanning under the drive of the actuator.

[0019] This application embodiment also provides a near-eye display device, which is used as a head-mounted augmented reality device, and includes at least a near-eye display module and a scanning display device according to the above description, wherein the scanning display device is disposed in the near-eye display module.

[0020] This application embodiment also provides a near-eye display device, which is used as a head-mounted virtual reality device, and includes at least a near-eye display module and a scanning display device according to the above description, wherein the scanning display device is disposed in the near-eye display module.

[0021] The technical solutions adopted in the embodiments of this application can achieve the following technical effects:

[0022] In this embodiment, by reasonably optimizing the focal length of the eight coaxial lenses of the optical imaging lens group, the optical power of the system can be reasonably dispersed, the aberrations generated by the lenses can be reduced, and the purpose of correcting various aberrations can be achieved, thereby realizing clear imaging of the image surface while improving the field of view.

[0023] Furthermore, by configuring a reasonable number of lenses, the overall structure of the optical imaging lens group is made more compact, meeting the production needs of miniaturized mass production of lens products. By combining aspherical and spherical lenses, using single lenses and cemented lenses appropriately, and limiting the radial maximum effective half-aperture of some lenses in a related proportion, the correction of various optical aberrations is further enhanced, achieving clear imaging. At the same time, the size and weight of the optical imaging lens group are further reduced.

[0024] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the technical solutions of this application. The objectives and other advantages of this application may be realized and obtained by means of the structures and / or processes particularly pointed out in the description, claims and drawings. Attached Figure Description

[0025] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0026] Figure 1a , 1b This is an illustrative structural diagram of a scanning display system;

[0027] Figure 2a This is a schematic diagram of the scanning output of the fiber optic scanner provided in an embodiment of this application;

[0028] Figure 2b This is a schematic diagram of the maximum effective half-aperture of a portion of the optical imaging lens group provided in the embodiments of this application along the radial direction;

[0029] Figure 3 This is a schematic diagram of the structure of an optical imaging lens assembly provided in Embodiment 1 of this application;

[0030] Figure 4 This is the MTF curve of the optical imaging lens group in Embodiment 1 of this application;

[0031] Figure 5 This is a field curvature distortion curve of the optical imaging lens group in Embodiment 1 of this application;

[0032] Figure 6 This is the chromatic aberration diagram of the optical imaging lens group in Embodiment 1 of this application.

[0033] Figure 7 This is a schematic diagram of the structure of an optical imaging lens assembly provided in Embodiment 2 of this application;

[0034] Figure 8 This is the MTF curve of the optical imaging lens group in Embodiment 2 of this application;

[0035] Figure 9 This is a field curvature distortion curve of the optical imaging lens group in Embodiment 2 of this application;

[0036] Figure 10 This is the transverse chromatic aberration diagram of the optical imaging lens group in Embodiment 2 of this application;

[0037] Figure 11 This is a schematic diagram of the structure of an optical imaging lens assembly provided in Embodiment 3 of this application;

[0038] Figure 12 This is the MTF curve of the optical imaging lens group in Embodiment 3 of this application;

[0039] Figure 13 This is a field curvature distortion curve of the optical imaging lens group in Embodiment 3 of this application;

[0040] Figure 14 This is the transverse chromatic aberration diagram of the optical imaging lens group in Embodiment 3 of this application;

[0041] Figure 15 This is a schematic diagram of the structure of an optical imaging lens assembly provided in Embodiment 4 of this application;

[0042] Figure 16 This is the MTF curve of the optical imaging lens group in Embodiment 4 of this application;

[0043] Figure 17 This is a field curvature distortion curve of the optical imaging lens group in Embodiment 4 of this application;

[0044] Figure 18This is the transverse chromatic aberration diagram of the optical imaging lens group in Embodiment 4 of this application;

[0045] Figure 19 This is a schematic diagram of the structure of an optical imaging lens assembly provided in Embodiment 5 of this application;

[0046] Figure 20 This is the MTF curve of the optical imaging lens group in Embodiment 5 of this application;

[0047] Figure 21 This is a field curvature distortion curve of the optical imaging lens group in Embodiment 5 of this application;

[0048] Figure 22 This is the chromatic aberration diagram of the optical imaging lens group in Embodiment 5 of this application.

[0049] Icons: 100-Processor; 110-Laser group; 120-Fiber optic scanning module; 130-Transmission fiber; 140-Light source modulation circuit; 150-Scanning drive circuit; 160-Beam combining unit; 121-Scanning actuator; 121a-Slow axis; 121b-Fast axis; 122-Fiber optic cantilever; 123-Mirror group; 124-Scanner package; 125-Fiber optic fixture; 230-Scanning surface; 240-Imaging plane; 11-First lens; 12-Second lens; 13-Second lens; Three lenses; 14-Fourth lens; 141, 142-Fourth sub-lens; 15-Fifth lens; 16-Sixth lens; 161, 162-Sixth sub-lens; 17-Seventh lens; 18-Eighth lens; 01-Aperture stop; 02-Scanning surface; 31-First lens; 32-Second lens; 33-Third lens; 34-Fourth lens; 341, 342-Fourth sub-lens; 35-Fifth lens; 36-Sixth lens; 361, 362-Sixth sub-lens; 37-Seventh lens; 38 - Eighth lens; 03 - Aperture stop; 04 - Scanning surface; 51 - First lens; 52 - Second lens; 53 - Third lens; 54 - Fourth lens; 541, 542 - Fourth sub-lens; 55 - Fifth lens; 56 - Sixth lens; 561, 562 - Sixth sub-lens; 57 - Seventh lens; 58 - Eighth lens; 05 - Aperture stop; 06 - Scanning surface; 71 - First lens; 72 - Second lens; 73 - Third lens; 74 - Fourth lens; 741, 742 - Fourth sub-lens Sub-lens; 75-Fifth lens; 76-Sixth lens; 761, 762-Sixth sub-lens; 77-Seventh lens; 78-Eighth lens; 07-Aperture stop; 08-Scanning surface; 91-First lens; 92-Second lens; 93-Third lens; 94-Fourth lens; 941, 942-Fourth sub-lens; 95-Fifth lens; 96-Sixth lens; 961, 962-Sixth sub-lens; 97-Seventh lens; 98-Eighth lens; 09-Aperture stop; 10-Scanning surface. Detailed Implementation

[0050] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0051] Illustrative scanning display system

[0052] Current scanning display imaging can be implemented using micro-electro-mechanical systems (MEMS) or fiber scanning display (FSD) devices. The FSD approach, as a novel scanning display imaging method, uses a fiber optic scanner to achieve image scanning output. To enable those skilled in the art to clearly understand the scheme of this application, a brief explanation of the principles and corresponding system of fiber optic scanning imaging is provided below.

[0053] like Figure 1a The image shown is an illustrative scanning display system according to this application, which mainly includes:

[0054] The system includes a processor 100, a laser assembly 110, a fiber optic scanning module 120, a transmission fiber optic cable 130, a light source modulation circuit 140, a scanning drive circuit 150, and a beam combining unit 160.

[0055] The processor 100 can be a graphics processing unit (GPU), a central processing unit (CPU), or other chips or circuits with control and image processing functions, without being specifically limited here.

[0056] When the system is in operation, the processor 100 controls the light source modulation circuit 140 to modulate the laser group 110 according to the image data to be displayed. The laser group 110 contains multiple monochromatic lasers, each emitting a beam of a different color. As shown in Figure 1, the laser group can specifically use red (R), green (G), and blue (B) lasers. The beams emitted by each laser in the laser group 110 are combined into a single laser beam by the beam combining unit 160 and coupled into the transmission optical fiber 130.

[0057] The processor 100 can also control the scanning drive circuit 150 to drive the fiber scanner in the fiber scanning module 120 to perform scanning, thereby scanning and outputting the beam transmitted in the transmission fiber 130.

[0058] A beam of light output from a fiber optic scanner acts on a specific pixel on the surface of a medium, forming a light spot at that pixel, thus achieving scanning of that pixel location. Driven by the fiber optic scanner, the output end of the transmission fiber 130 sweeps along a specific scanning trajectory, causing the beam to move to the corresponding pixel location. During the actual scanning process, the beam output from the transmission fiber 130 forms a light spot with corresponding image information (such as color, grayscale, or brightness) at each pixel location. Within one frame, the beam traverses each pixel location at a sufficiently high speed to complete the scanning of one frame of the image. Due to the "visual persistence" characteristic of human vision, the human eye cannot perceive the movement of the beam at each pixel location, but instead sees a complete image frame.

[0059] Continue to refer to Figure 1b The specific structure of the fiber optic scanning module 120 includes: a scanning actuator 121, a fiber optic cantilever 122, a mirror assembly 123, a scanner housing 124, and a fixing member 125. The scanning actuator 121 is fixed to the scanner housing 124 by the fixing member 125. The transmission fiber 130 extends from the front end of the scanning actuator 121 to form the fiber optic cantilever 122 (also called the scanning fiber). During operation, driven by the scanning drive signal, the slow axis 121a (also called the first actuation part) of the scanning actuator 121 moves along the vertical direction (this vertical direction is parallel to the...). Figure 1a , 1b The Y-axis in the reference coordinate system (in this application, the vertical direction can also be referred to as the first direction) vibrates, and its fast axis 121b (also referred to as the second actuator) vibrates along the horizontal direction (this horizontal direction is parallel to the reference coordinate system). Figure 1a , 1b The X-axis in the reference coordinate system (in this application, this horizontal direction can also be referred to as the second direction) vibrates, driven by the scanning actuator 121. The front end of the fiber optic cantilever 122 performs a two-dimensional sweep along a preset trajectory and emits a light beam. The emitted light beam can then pass through the mirror assembly 123 to achieve scanning imaging. Generally, the structure composed of the scanning actuator 121 and the fiber optic cantilever 122 can be called a fiber optic scanner.

[0060] like Figure 2aAs shown in this embodiment, the motion trajectory of the optical fiber output end forms a scanning surface 230 through the movement of the fast and slow axes. After passing through the corresponding lens group 123, it is converted into an imaging plane 240 (when imaging is performed on a planar carrier, the image is a plane; it should be noted that in other embodiments of the present invention, the image formed after passing through the lens group 123 can correspond to the surface of the imaging carrier, that is, it can change with the shape of the carrier surface, as long as the image is clear). When applied to near-eye display devices such as augmented reality (AR) devices, the imaging plane 240 is coupled into the waveguide as the entrance pupil of the waveguide for imaging so that the human eye can view it.

[0061] To facilitate description and enable those skilled in the art to easily understand the solution of this application, it should be noted that the optical imaging lens assembly in this application (such as...) Figure 2a The lens group 123 shown serves as an eyepiece. Through the action of this optical imaging lens group, the scanning surface 230 can be converted into an imaging plane 240 (in practical applications, the direction of light transmission is from the scanning surface 230 to the imaging plane 240). Therefore, the side of the optical imaging lens group corresponding to the imaging plane 240 is referred to as the first side, and the side of the optical imaging lens group corresponding to the scanning surface 230 is referred to as the second side. In the following description, "first side" and "second side" will be used as references to describe the embodiment of the optical imaging lens group. Furthermore, in the description of the subsequent embodiments, such as for a certain lens in the optical imaging lens group, "the first side surface of the Xth lens" refers to the surface of the Xth lens facing the first side.

[0062] It should be further noted that in the field of projection, the image corresponding to the first side is a planar image, and the corresponding planar image carrier can be such as a projection screen, a screen, or a wall. The image corresponding to the second side is a curved image, that is, an arc-shaped scanning surface scanned by a fiber optic scanner or emitted by other image sources. In the application scenario of the camera field, the optical path is reversed in the field of projection. The first side generally corresponds to the object side that collects image information, and the second side generally corresponds to the image side that is captured and formed.

[0063] Optical imaging lens

[0064] The optical imaging lens assembly in this embodiment includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged coaxially from the first side to the second side. The focal lengths of the first lens, second lens, third lens, and sixth lens are negative, positive, positive, and positive, respectively. It should be noted that by setting a reasonable number of lenses and limiting the positive and negative focal lengths of the first to third lenses and the sixth lens, the optical power of the system can be reasonably dispersed, aberrations generated by the lenses can be reduced, and the purpose of correcting various aberrations can be achieved. This results in clear imaging of the image surface while improving the field of view. Furthermore, it should be emphasized that limiting the focal lengths of the third and sixth lenses to positive can enhance the converging ability of the curved image to balance aberrations.

[0065] Furthermore, in a preferred embodiment of this application, the focal lengths of the fourth lens, fifth lens, seventh lens, and eighth lens are negative, positive, positive, and positive, respectively. It should be emphasized that in other embodiments of this application, the positive or negative nature of the focal lengths of the fourth lens, fifth lens, seventh lens, and eighth lens is not limited as in the embodiments of this application; they can be either positive or negative.

[0066] More preferably, in the embodiments provided by the present invention, the first lens, second lens, third lens, fourth lens, sixth lens, and eighth lens are all spherical lenses; the fifth lens and seventh lens are both aspherical lenses. Furthermore, the fourth lens and sixth lens are both cemented spherical lenses. It should be noted that by rationally configuring and using aspherical and spherical lenses among the eight lenses, and by rationally using single lenses and cemented lenses, the correction of various optical aberrations is further enhanced, achieving clear imaging while expanding the field of view. It should be emphasized that by designing the lens surface structure of the lenses in reasonable positions and in reasonable quantities (the fifth and seventh lenses) as aspherical surface structures, more control variables can be obtained to reduce aberrations and rationally reduce the number of lenses. Therefore, while improving image display quality, it also contributes to the miniaturization or micronization of the optical imaging lens group. In addition, the aspherical lens defined above refers to a lens whose first and second side surfaces are both aspherical surface structures, and can be understood as the entire or a portion of the optically effective area of ​​the lens surface being aspherical.

[0067] More specifically and preferably, in this embodiment of the invention, both the fourth lens and the sixth lens, as cemented spherical lenses, have two sub-lenses. Preferably, the two sub-lenses of the fourth lens are arranged along the optical axis from the first side to the second side, and their corresponding focal lengths are positive and negative, respectively; similarly, the two sub-lenses of the sixth lens are arranged along the optical axis from the first side to the second side, and their corresponding focal lengths are negative and positive, respectively. It should be noted that by limiting the focal lengths of the corresponding sub-lenses of the fourth and sixth lenses, chromatic aberration and spherical aberration can be effectively eliminated, which is crucial for aberration correction of the entire imaging lens group. Of course, in some embodiments of the invention, the focal lengths of both sub-lenses of the fourth lens can also be negative, and the focal lengths of both sub-lenses of the sixth lens can also be positive. It should be emphasized that in other embodiments of the invention, the number of sub-lenses corresponding to the fourth and sixth lenses is not limited to the number provided in this embodiment; it can also be other numbers of sub-lenses, such as 3 or 4, and can be flexibly set according to actual design needs.

[0068] Furthermore, in the optical imaging lens assembly provided in this embodiment of the invention, the second side surface of the sub-lens of the fourth lens near the fifth lens is concave, and the first side surface of the fifth lens is also concave. It should be noted that by concavely restricting the two opposing surfaces of the fourth and fifth lenses (i.e., the second side surface of the sub-lens of the fourth lens near the fifth lens and the first side surface of the fifth lens), a larger image field curvature can be generated to match the curvature of the image plane, thereby achieving a good aberration correction effect.

[0069] It should also be noted that, as mentioned in this article, the first side surface is convex, meaning that the first side surface forms a raised shape in the direction of the first side of the optical imaging lens group; the first side surface is concave, meaning that the first side surface forms a recessed shape in the direction of the first side of the optical imaging lens group; the second side surface is convex, meaning that the second side surface forms a raised shape in the direction of the second side of the optical imaging lens group; the second side surface is concave, meaning that the second side surface forms a recessed shape in the direction of the second side of the optical imaging lens group.

[0070] Furthermore, in some embodiments, the lens surface is not entirely concave or convex; the lens surface may be a composite curved surface, or the near-optical axis portion may be curved while the edge portion is not curved. In particular, optionally, when the lens surface is convex and the position of the convex surface is not defined, it means that the convex surface can be located near the optical axis of the lens surface. Similarly, when the lens surface is concave and the position of the concave surface is not defined, it means that the concave surface can be located near the optical axis of the lens surface.

[0071] Furthermore, in the optical imaging lens group provided in the embodiments of the present invention, the first lens and the optical imaging lens group have the following relationship: 0.7 ≤ |f1 / f 总|≤1.2, where f1 is the focal length of the first lens, f 总 This represents the total focal length of the optical imaging lens group; additionally, the sub-lens of the fourth lens closest to the fifth lens has the following relationship with the optical imaging lens group: 0.8 ≤ |f 4-2 / f 总 |≤1.5, where f 4-2 f is the focal length of the sub-lens of the fourth lens that is closest to the fifth lens. 总 The focal length is the total focal length of the optical imaging lens group. It should be noted that by defining the focal length ratio between the first lens and the total focal length of the optical imaging lens group, and by defining the focal length ratio between the sub-lens of the fourth lens (close to the fifth lens) and the total focal length of the optical imaging lens group, the optical power of the system is reasonably distributed and configured, thereby further enhancing the correction of various aberrations and improving the field of view and image quality. Additionally, if the location of the lens focal length is not defined in this embodiment, it means that the focal length of the lens can be the focal length of the lens near the optical axis. It should be emphasized that prior to this invention, existing optical imaging lens groups for projection displays could not achieve a balance between image quality and a large field of view; that is, they typically reduced image quality while increasing the field of view, and could not achieve a large field of view while maintaining image quality. The invention of this application achieves high-quality image output while improving the field of view and miniaturization by defining and rationally configuring the corresponding features (focal length, spherical and aspherical, single lens and cemented lens, and surface structure, etc.) of the corresponding lenses among the eight lenses.

[0072] Furthermore, in order to achieve a balance between image quality and wide field of view performance in the optical imaging lens assembly of the present invention, and to ensure that both are in their optimal state, the preferred embodiment of the present invention has the following limitations: First, it should be noted that, please refer to... Figure 2b and combination Figure 3 The maximum effective half-aperture of the third lens along the radial direction is Y1. The maximum effective half-aperture of the two opposite surfaces of the fourth and fifth lenses along the radial direction is the same and is Y2. The maximum effective half-aperture of the seventh lens along the radial direction is Y3. Among them, Y1 and Y2 have the following relationship: 1≤Y1 / Y2≤1.4; Y2 and Y3 have the following relationship: 1.4≤Y3 / Y2≤1.7.

[0073] Furthermore, in one possible implementation, the eight lenses can be connected by spacing or by adhesive bonding, depending on the needs of the actual application, and no limitation is imposed here.

[0074] Alternatively, in one possible implementation, the first to eighth lenses are all made of plastic or glass. It should be noted that using plastic for the first to eighth lenses can effectively reduce production costs. Compared to glass, the cost of plastic lenses is one-twentieth to one-tenth of that of glass lenses, thus greatly benefiting low-cost mass production. Furthermore, plastic lenses are typically injection molded, which is easy to process and can be readily fabricated into various aspherical surface structures. Plastic also reduces the overall weight of the lens, facilitating lightweight product design. When using glass, its higher and wider refractive index offers advantages in correcting lens aberrations. Glass also has a much lower coefficient of thermal expansion, which is beneficial for precision assembly. Additionally, glass's inherent resistance to high temperatures, ultraviolet radiation, and acids and alkalis gives the lens assembly a strong advantage in terms of lifespan and performance stability. It should be emphasized that other embodiments of the present invention are not limited to the plastic and glass materials provided in the embodiments of the present invention; other materials suitable for making lenses can also be used.

[0075] It should also be noted that, optionally, the optical imaging lens group disclosed in the embodiments of the present invention may be provided with at least one aperture stop, which may be located in front of the first lens (first side), between each lens, or after the last eighth lens (second side). The aperture stop may be of the type such as an aperture stop or a field stop, which can be used to reduce stray light and help improve the image display quality.

[0076] Embodiment one

[0077] Figure 3 This is a schematic diagram of an optical imaging lens assembly provided in an embodiment of the present invention. The optical imaging lens assembly includes a first side (i.e., Figure 3 From the side where aperture 01 is located to the second side (that is, Figure 3 The first lens 11, the second lens 12, the third lens 13, the fourth lens 14, the fifth lens 15, the sixth lens 16, the seventh lens 17 and the eighth lens 18 are arranged sequentially along the common optical axis on the side where the scanning surface 02 is located.

[0078] In this embodiment, each pair of adjacent lenses in the first lens 11, second lens 12, third lens 13, fourth lens 14, fifth lens 15, sixth lens 16, seventh lens 17, and eighth lens 18 is spaced apart, and the first lens 11, second lens 12, third lens 13, fifth lens 15, seventh lens 17, and eighth lens 18 are six single non-bonded lenses. The fourth lens 14 is a cemented lens composed of two sub-lenses, with the two sub-lenses being fourth sub-lens 141 and fourth sub-lens 142 from the first side to the second side; the sixth lens 16 is also a cemented lens composed of two lenses, with the two sub-lenses being sixth sub-lens 161 and sixth sub-lens 162 from the first side to the second side.

[0079] The focal lengths of the first lens 11 to the eighth lens 18 from the first side to the second side are negative, positive, positive, negative, positive, positive, positive and positive, respectively. The fourth lens 14 includes the fourth sub-lens 141 and the fourth sub-lens 142, whose focal lengths are positive and negative, respectively. The sixth lens 16 includes the sixth sub-lens 161 and the sixth sub-lens 162, whose focal lengths are negative and positive, respectively.

[0080] The first and second side surfaces of the first lens 11 are both concave near the optical axis;

[0081] The first side surface of the second lens 12 is concave near the optical axis, and the second side surface is convex.

[0082] Both the first and second side surfaces of the third lens 13 are convex.

[0083] The first and second side surfaces of the fourth sub-lens 141 in the fourth lens 14 are both convex, and the first and second side surfaces of the fourth sub-lens 142 are both concave.

[0084] The first side surface of the fifth lens 15 is concave near the optical axis, and the second side surface is convex near the optical axis;

[0085] In the sixth lens 16, the first and second side surfaces of the sixth sub-lens 161 are both concave, and the first and second side surfaces of the sixth sub-lens 162 are both convex.

[0086] The first side surface of the seventh lens 17 is convex near the optical axis, and the second side surface is concave near the optical axis;

[0087] The first side surface of the eighth lens 18 is convex, and the second side surface is concave near the optical axis.

[0088] In this embodiment, the focal lengths of the first lens 11 and the fourth lens 14 in the optical imaging lens group satisfy the following relationship:

[0089] 0.7≤|f1 / f总 |≤1.2,0.8≤|f 4-2 / f 总 |≤1.5, where f1 is the focal length of the first lens, f 4-2 f is the focal length of the sub-lens of the fourth lens 14 that is closest to the fifth lens 15, which is also the focal length of the fourth sub-lens 142. 总 This represents the total focal length of the optical imaging lens group. It should be noted that the specific focal length values ​​for each lens are shown in Table 1:

[0090] Table 1. Focal length parameters of each lens in the optical imaging lens group.

[0091] Lens Focal length Lens focal length / total lens focal length First lens 11 -2.86 -1.11 Second lens 12 7.17 2.78 Third lens 13 3.82 1.48 Fourth lens 14 -12.02 -4.66 Fourth sub-lens 141 3.9 1.51 Fourth sub-lens 142 -2.21 -0.86 Fifth lens 15 61.18 23.71 Sixth lens 16 40.01 15.51 Sixth sub-lens 161 -6.69 -2.59 Sixth sub-lens 162 11.05 4.28 Seventh lens 17 9.1 3.53 Eighth lens 18 64.08 24.84

[0092] The refractive indices and dispersion coefficients of the first lens 11, the fourth sub-lens 142, and the sixth sub-lens 161 in the optical imaging lens group satisfy the following conditions:

[0093] The refractive index and dispersion coefficient of the first lens 11 are 1.92 and 20.9, respectively; the refractive index and dispersion coefficient of the fourth sub-lens 142 are 1.85 and 23.8, respectively; and the refractive index and dispersion coefficient of the sixth sub-lens 161 are 1.92 and 20.9, respectively.

[0094] In the optical imaging lens assembly provided in Embodiment 1 of the present invention, the total focal length of the optical imaging lens assembly is 2.58 mm, and the field of view is 28 degrees. The parameters of the radius of curvature, thickness, refractive index, and dispersion coefficient of each lens used to image the scanning surface O2 are shown in Table 2.

[0095] Table 2 Structural parameters of the optical imaging lens assembly in Example 1

[0096]

[0097] It should be noted that Tables 1 and 2 are detailed structural data of the optical imaging lens group of Embodiment 1. The units of radius of curvature, thickness and focal length are all in millimeters. Surfaces 0-20 in Table 2 represent the surfaces from the first side to the second side in sequence. An optical surface with an "infinite" radius of curvature in the imaging plane refers to a plane.

[0098] Furthermore, the conicity and asphericity of the surfaces corresponding to the fifth lens 15 and the seventh lens 17 (both aspherical lenses) are shown in Table 3 below:

[0099] Table 3. Conicity and asphericity data of the aspherical lens surface in Example 1.

[0100] Surface k A4 A6 A8 A10 A12 A14 A16 11 -7.5E-01 1.6E-01 -5.4E-02 6.4E-02 -4.9E-02 2.6E-02 -9.3E-03 2.9E-03 12 -1.2E+00 4.5E-04 -1.4E-03 1.1E-03 -1.8E-04 -1.1E-04 4.6E-05 -3.0E-06 16 -6.9E-01 -6.3E-03 -1.4E-03 -1.5E-04 8.3E-04 -5.2E-04 1.4E-04 -1.4E-05 17 -1.1E+00 -4.1E-02 2.5E-03 6.5E-03 -5.9E-03 2.4E-03 -4.6E-04 3.4E-05

[0101] Table 3 shows the conic coefficient and aspheric coefficient data in Example 1, where k is the conic coefficient in the aspheric curve equation, and A4 to A16 represent the 4th to 16th order aspheric coefficients of each surface.

[0102] Additionally, please refer to the following: Figure 2b and Figure 3 In this embodiment, the maximum effective half-aperture Y1 of the third lens along the radial direction, the maximum effective half-aperture Y2 of the two opposite surfaces of the fourth and fifth lenses along the radial direction, and the maximum effective half-aperture Y3 of the seventh lens along the radial direction satisfy the following relationship: Y1 / Y2=1.47, Y3 / Y2=1.8.

[0103] Furthermore, tests showed that when the image light corresponding to the scanning surface is projected using the aforementioned optical imaging lens group, its optical transfer function curve is as follows: Figure 4 As shown, the field distortion curve is as follows: Figure 5 As shown, the vertical axis color difference curve is as follows: Figure 6 As shown; among them, the Modulation Transfer Function (MTF) curve represents the overall resolution level of an optical system, the Field Curve Distortion curve represents the F-Tan (theta) distortion magnitude (percentage) under different field angles, and the Vertical Chromatic Aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axial direction.

[0104] Depend on Figures 4-6 Observations show that the optical imaging lens group in Example 1 has good imaging resolution, small optical system distortion and chromatic aberration across the entire field of view. Therefore, the optical imaging lens group can clearly image the scanning surface image of the fiber optic scanner and has good imaging effect.

[0105] Of course, in practical applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element can be set on the second side of the optical imaging lens assembly, and the optical imaging lens assembly can be installed in the housing. This allows the curved image formed by the image source (such as a fiber optic scanner) to be imaged onto a flat carrier, thus achieving clear imaging.

[0106] Embodiment two

[0107] Figure 7 This is a schematic diagram of an optical imaging lens assembly provided in an embodiment of the present invention. The optical imaging lens assembly includes a first side (i.e., Figure 7 From the side where aperture 03 is located (i.e., the second side) to the third side (i.e., Figure 7 The first lens 31, the second lens 32, the third lens 33, the fourth lens 34, the fifth lens 35, the sixth lens 36, the seventh lens 37 and the eighth lens 38 are arranged sequentially along the common optical axis on the side where the scanning surface 04 is located.

[0108] In this embodiment, each pair of adjacent lenses in the first lens 31, second lens 32, third lens 33, fourth lens 34, fifth lens 35, sixth lens 36, seventh lens 37, and eighth lens 38 is spaced apart, and the first lens 31, second lens 32, third lens 33, fifth lens 35, seventh lens 37, and eighth lens 38 are six single non-bonded lenses. The fourth lens 34 is a cemented lens composed of two sub-lenses, with the two sub-lenses being fourth sub-lens 341 and fourth sub-lens 342 from the first side to the second side; the sixth lens 36 is also a cemented lens composed of two lenses, with the two sub-lenses being sixth sub-lens 361 and sixth sub-lens 362 from the first side to the second side.

[0109] The focal lengths of the first lens 31 to the eighth lens 38 from the first side to the second side are negative, positive, positive, negative, positive, positive, positive and negative, respectively. The fourth lens 34 includes the fourth sub-lens 341 and the fourth sub-lens 342, whose focal lengths are positive and negative, respectively. The sixth lens 36 includes the sixth sub-lens 361 and the sixth sub-lens 362, whose focal lengths are negative and positive, respectively.

[0110] Both the first and second side surfaces of the first lens 31 are concave near the optical axis;

[0111] The first side surface of the second lens 32 is concave near the optical axis, and the second side surface is convex.

[0112] The first and second side surfaces of the third lens 33 are both convex surfaces;

[0113] The first and second side surfaces of the fourth sub-lens 341 in the fourth lens 34 are both convex, and the first and second side surfaces of the fourth sub-lens 342 are both concave.

[0114] The first side surface of the fifth lens 35 is concave near the optical axis, and the second side surface is convex near the optical axis;

[0115] In the sixth lens 36, the first side surface of the sixth sub-lens 361 is convex and the second side surface is concave; the first side surface and the second side surface of the sixth sub-lens 362 are both convex.

[0116] The first side surface of the seventh lens 37 is convex near the optical axis, and the second side surface is concave near the optical axis;

[0117] The first side surface of the eighth lens 38 is convex, and the second side surface is concave near the optical axis.

[0118] In this embodiment, the focal lengths of the first lens 31 and the fourth lens 34 in the optical imaging lens group satisfy the following relationship:

[0119] 0.7≤|f1 / f 总 |≤1.2,0.8≤|f 4-2 / f 总 |≤1.5, where f1 is the focal length of the first lens, f 4-2 f is the focal length of the sub-lens of the fourth lens 34 that is closest to the fifth lens 35, which is also the focal length of the fourth sub-lens 342. 总 This represents the total focal length of the optical imaging lens group. It should be noted that the specific focal length values ​​for each lens are shown in Table 4:

[0120] Table 4. Focal length parameters of each lens in the optical imaging lens group.

[0121] Lens Focal length Lens focal length / total lens focal length First lens 31 -2.53 -0.99 Second lens 32 6.38 2.50 Third lens 33 3.61 1.41 Fourth lens 34 -12.10 -4.75 Fourth sub-lens 341 5.74 2.25 Fourth sub-lens 342 -3.01 -1.18 Fifth lens 35 -16.14 -6.33 Sixth lens 36 22.04 8.64 Sixth sub-lens 361 -15.40 -6.04 Sixth sub-lens 362 22.90 8.98 Seventh lens 37 6.01 2.36 Eighth lens 38 -23.16 -9.08

[0122] The refractive indices and dispersion coefficients of the first lens 31, the fourth sub-lens 342, and the sixth sub-lens 361 in the optical imaging lens group satisfy the following conditions:

[0123] The refractive index and dispersion coefficient of the first lens 31 are 1.95 and 17.9, respectively; the refractive index and dispersion coefficient of the fourth sub-lens 342 are 1.78 and 25.7, respectively; and the refractive index and dispersion coefficient of the sixth sub-lens 361 are 1.92 and 18.89, respectively.

[0124] In the optical imaging lens assembly provided in Embodiment 2 of the present invention, the total focal length of the optical imaging lens assembly is 2.58 mm, and the field of view is 28 degrees. The parameters of the radius of curvature, thickness, refractive index, and dispersion coefficient of each lens used to image the scanning surface 04 are shown in Table 5.

[0125] Table 5 Structural parameters of the optical imaging lens assembly in Example 2

[0126]

[0127]

[0128] It should be noted that Tables 4 and 5 are detailed structural data of the optical imaging lens group in Embodiment 2. The units of radius of curvature, thickness and focal length are all in millimeters. In Table 5, surfaces 0-20 represent the surfaces from the first side to the second side in sequence. An optical surface with an "infinite" radius of curvature in the imaging plane refers to a plane.

[0129] Furthermore, the aspherical conic coefficients of the surfaces corresponding to the fifth lens 35 and the seventh lens 37 (both aspherical lenses) are shown in Table 6 below:

[0130] Table 6. Conicity and asphericity data of the aspherical lens surface in Example 2.

[0131] Surface k A4 A6 A8 A10 A12 A14 A16 11 -9.83E-01 6.19E-02 -2.18E-02 -9.85E-04 3.42E-02 -5.23E-02 3.47E-02 -8.51E-03 12 -1.10E+00 -2.14E-02 1.43E-02 -1.15E-02 7.37E-03 -3.01E-03 6.84E-04 -6.44E-05 16 -9.81E-01 -1.45E-02 8.92E-03 -6.56E-03 4.10E-03 -1.64E-03 3.49E-04 -2.96E-05 17 -5.03E+00 -1.23E-03 -1.35E-02 1.48E-02 -1.04E-02 4.09E-03 -7.93E-04 5.82E-05

[0132] Table 6 shows the conic coefficient and aspheric coefficient data in Example 2, where k is the conic coefficient in the aspheric curve equation, and A4 to A16 represent the 4th to 16th order aspheric coefficients of each surface.

[0133] Additionally, please refer to the following: Figure 2b and Figure 7 In this embodiment, the maximum effective half-aperture Y1 of the third lens along the radial direction, the maximum effective half-aperture Y2 of the two opposite surfaces of the fourth and fifth lenses along the radial direction, and the maximum effective half-aperture Y3 of the seventh lens along the radial direction satisfy the following relationship: Y1 / Y2=1.37, Y3 / Y2=1.7.

[0134] Furthermore, tests showed that when the image light corresponding to the scanning surface is projected using the aforementioned optical imaging lens group, its optical transfer function curve is as follows: Figure 8 As shown, the field distortion curve is as follows: Figure 9 As shown, the vertical axis color difference curve is as follows: Figure 10 As shown; among them, the Modulation Transfer Function (MTF) curve represents the overall resolution level of an optical system, the Field Curve Distortion curve represents the F-Tan (theta) distortion magnitude (percentage) under different field angles, and the Vertical Chromatic Aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axial direction.

[0135] Depend on Figures 8-10 Observations show that the optical imaging lens group of Example 2 has good imaging resolution and small optical system distortion and chromatic aberration across the entire field of view. Therefore, the optical imaging lens group can clearly image the scanning surface image of the fiber optic scanner and has good imaging effect.

[0136] Of course, in practical applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element can be set on the second side of the optical imaging lens assembly, and the optical imaging lens assembly can be installed in the housing. This allows the curved image formed by the image source (such as a fiber optic scanner) to be imaged onto a flat carrier, thus achieving clear imaging.

[0137] Embodiment three

[0138] Figure 11 This is a schematic diagram of an optical imaging lens assembly provided in an embodiment of the present invention. The optical imaging lens assembly includes a first side (i.e., Figure 11 From the side where aperture 05 is located (to the second side, that is, Figure 11The first lens 51, the second lens 52, the third lens 53, the fourth lens 54, the fifth lens 55, the sixth lens 56, the seventh lens 57 and the eighth lens 58 are arranged sequentially along the common optical axis on the side where the scanning surface 06 is located.

[0139] In this embodiment, each pair of adjacent lenses in the first lens 51, second lens 52, third lens 53, fourth lens 54, fifth lens 55, sixth lens 56, seventh lens 57, and eighth lens 58 is spaced apart, and the first lens 51, second lens 52, third lens 53, fifth lens 55, seventh lens 57, and eighth lens 58 are six single non-bonded lenses. The fourth lens 54 is a cemented lens composed of two sub-lenses, with the two sub-lenses being fourth sub-lens 541 and fourth sub-lens 542 from the first side to the second side; the sixth lens 56 is also a cemented lens composed of two lenses, with the two sub-lenses being sixth sub-lens 561 and sixth sub-lens 562 from the first side to the second side.

[0140] The focal lengths of the first lens 51 to the eighth lens 58 from the first side to the second side are negative, positive, positive, negative, positive, positive, negative and positive, respectively. The fourth lens 54 includes the fourth sub-lens 541 and the fourth sub-lens 542, which have negative and negative focal lengths, respectively. The sixth lens 56 includes the sixth sub-lens 561 and the sixth sub-lens 562, which have positive and positive focal lengths, respectively.

[0141] Both the first and second side surfaces of the first lens 51 are concave near the optical axis;

[0142] Both the first and second side surfaces of the second lens 52 are convex.

[0143] The first and second side surfaces of the third lens 53 are both convex surfaces;

[0144] The first side surface of the fourth sub-lens 541 in the fourth lens 54 is concave near the optical axis, and the second side surface is convex. The first side surface and the second side surface of the fourth sub-lens 542 are both concave.

[0145] The first side surface of the fifth lens 55 is concave near the optical axis, and the second side surface is convex near the optical axis;

[0146] In the sixth lens 56, the first side surface of the sixth sub-lens 561 is convex and the second side surface is concave; the first side surface and the second side surface of the sixth sub-lens 562 are both convex.

[0147] The first side surface of the seventh lens 57 is convex near the optical axis, and the second side surface is concave near the optical axis;

[0148] The first side surface of the eighth lens 58 is convex, and the second side surface is concave near the optical axis.

[0149] In this embodiment, the focal lengths of the first lens 51 and the fourth lens 54 in the optical imaging lens group satisfy the following relationship:

[0150] 0.7≤|f1 / f 总 |≤1.2,0.8≤|f 4-2 / f 总 |≤1.5, where f1 is the focal length of the first lens, f 4-2 f is the focal length of the sub-lens of the fourth lens 54 that is closest to the fifth lens 55, which is also the focal length of the fourth sub-lens 542. 总 This represents the total focal length of the optical imaging lens group. It should be noted that the specific focal length values ​​for each lens are shown in Table 7.

[0151] Table 7. Focal length parameters of each lens in the optical imaging lens group.

[0152] Lens Focal length Lens focal length / total lens focal length First lens 51 -1.94 -0.70 Second lens 52 3.18 1.15 Third lens 53 2.90 1.05 Fourth lens 54 -2.41 -0.87 Fourth sub-lens 541 -5.55 -2.01 Fourth sub-lens 542 -2.76 -1.00 Fifth lens 55 6.23 2.25 Sixth lens 56 7.32 2.65 Sixth sub-lens 561 22.90 8.28 Sixth sub-lens 562 27.08 9.79 Seventh lens 57 -2.36 -0.85 Eighth lens 58 2.04 0.74

[0153] The refractive indices and dispersion coefficients of the first lens 51, the fourth sub-lens 542, and the sixth sub-lens 561 in the optical imaging lens group satisfy the following conditions:

[0154] The refractive index and dispersion coefficient of the first lens 51 are 1.96 and 19.4, respectively; the refractive index and dispersion coefficient of the fourth sub-lens 542 are 1.82 and 22.4, respectively; and the refractive index and dispersion coefficient of the sixth sub-lens 561 are 1.89 and 20.2, respectively.

[0155] In the optical imaging lens assembly provided in Embodiment 3 of the present invention, the total focal length of the optical imaging lens assembly is 2.58 mm, and the field of view is 28 degrees. The parameters of the radius of curvature, thickness, refractive index, and dispersion coefficient of each lens used to image the scanning surface 06 are shown in Table 8.

[0156] Table 8 Structural parameters of the optical imaging lens assembly in Example 3

[0157]

[0158]

[0159] It should be noted that Tables 7 and 8 are detailed structural data of the optical imaging lens group in Embodiment 3. The units of radius of curvature, thickness and focal length are all in millimeters. In Table 8, surfaces 0-20 represent the surfaces from the first side to the second side in sequence. An optical surface with an "infinite" radius of curvature in the imaging plane refers to a plane.

[0160] Furthermore, the conicity and asphericity of the surfaces corresponding to the fifth lens 55 and the seventh lens 57 (both aspherical lenses) are shown in Table 9 below:

[0161] Table 9. Conicity and asphericity data of the aspherical lens surface in Example 3.

[0162] Surface k A4 A6 A8 A10 A12 A14 A16 11 -9.06E-01 2.82E-02 7.00E-02 -2.42E-02 4.35E-02 -5.16E-02 2.57E-02 -4.82E-03 12 -1.66E+00 -4.48E-02 1.66E-02 -8.28E-03 7.33E-03 -3.04E-03 6.71E-04 -6.89E-05 16 9.39E-02 2.62E-02 -1.25E-02 -4.29E-04 3.54E-03 -1.96E-03 4.82E-04 -4.90E-05 17 -1.43E+00 8.33E-02 1.40E-02 -1.08E-02 3.34E-03 1.23E-02 -8.69E-03 1.88E-03

[0163] Table 9 shows the conic coefficient and aspheric coefficient data of the aspherical lens surface in Example 3, where k is the conic coefficient in the aspherical curve equation, and A4 to A16 represent the 4th to 16th order aspheric coefficients of each surface.

[0164] Additionally, please refer to the following: Figure 2b and Figure 11 In this embodiment, the maximum effective half-aperture Y1 of the third lens along the radial direction, the maximum effective half-aperture Y2 of the two opposite surfaces of the fourth and fifth lenses along the radial direction, and the maximum effective half-aperture Y3 of the seventh lens along the radial direction satisfy the following relationship: Y1 / Y2=1.28, Y3 / Y2=1.53.

[0165] Furthermore, tests showed that when the image light corresponding to the scanning surface is projected using the aforementioned optical imaging lens group, its optical transfer function curve is as follows: Figure 12 As shown, the field distortion curve is as follows: Figure 13 As shown, the vertical axis color difference curve is as follows: Figure 14 As shown; among them, the Modulation Transfer Function (MTF) curve represents the overall resolution level of an optical system, the Field Curve Distortion curve represents the F-Tan (theta) distortion magnitude (percentage) under different field angles, and the Vertical Chromatic Aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axial direction.

[0166] Depend on Figures 12-14 Observations show that the optical imaging lens group in Example 3 has good imaging resolution, small optical system distortion and chromatic aberration across the entire field of view. Therefore, the optical imaging lens group can clearly image the scanning surface image of the fiber optic scanner and has good imaging effect.

[0167] Of course, in practical applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element can be set on the second side of the optical imaging lens assembly, and the optical imaging lens assembly can be installed in the housing. This allows the curved image formed by the image source (such as a fiber optic scanner) to be imaged onto a flat carrier, thus achieving clear imaging.

[0168] Embodiment four

[0169] Figure 15 This is a schematic diagram of an optical imaging lens assembly provided in an embodiment of the present invention. The optical imaging lens assembly includes a first side (i.e., Figure 15From the side where aperture 07 is located to the second side (that is, Figure 15 The first lens 71, the second lens 72, the third lens 73, the fourth lens 74, the fifth lens 75, the sixth lens 76, the seventh lens 77 and the eighth lens 78 are arranged sequentially along the common optical axis on the side where the scanning surface 08 is located.

[0170] In this embodiment, each pair of adjacent lenses in the first lens 71, second lens 72, third lens 73, fourth lens 74, fifth lens 75, sixth lens 76, seventh lens 77, and eighth lens 78 is spaced apart, and the first lens 71, second lens 72, third lens 73, fifth lens 75, seventh lens 77, and eighth lens 78 are six single non-bonded lenses. The fourth lens 74 is a cemented lens composed of two sub-lenses, with the two sub-lenses being fourth sub-lens 741 and fourth sub-lens 742 from the first side to the second side; the sixth lens 76 is also a cemented lens composed of two lenses, with the two sub-lenses being sixth sub-lens 761 and sixth sub-lens 762 from the first side to the second side.

[0171] The focal lengths of the first lens 71 to the eighth lens 78 from the first side to the second side are negative, positive, positive, positive, positive, positive, negative and positive, respectively. The fourth lens 74 includes the fourth sub-lens 741 and the fourth sub-lens 742, whose focal lengths are positive and negative, respectively. The sixth lens 76 includes the sixth sub-lens 761 and the sixth sub-lens 762, whose focal lengths are negative and positive, respectively.

[0172] Both the first and second side surfaces of the first lens 71 are concave near the optical axis;

[0173] Both the first and second side surfaces of the second lens 72 are convex.

[0174] The first side surface of the third lens 73 is concave near the optical axis, and the second side surface is convex.

[0175] The first and second side surfaces of the fourth sub-lens 741 in the fourth lens 74 are both convex surfaces, and the first and second side surfaces of the fourth sub-lens 742 are both concave surfaces.

[0176] The first side surface of the fifth lens 75 is concave near the optical axis, and the second side surface is convex near the optical axis;

[0177] In the sixth lens 76, the first and second side surfaces of the sixth sub-lens 761 are both concave, and the first and second side surfaces of the sixth sub-lens 762 are both convex.

[0178] The first side surface of the seventh lens 77 is convex near the optical axis, and the second side surface is concave near the optical axis;

[0179] The first side surface of the eighth lens 78 is convex, and the second side surface is concave near the optical axis.

[0180] In this embodiment, the focal lengths of the first lens 71 and the fourth lens 74 in the optical imaging lens group satisfy the following relationship:

[0181] 0.7≤|f1 / f 总 |≤1.2,0.8≤|f 4-2 / f 总 |≤1.5, where f1 is the focal length of the first lens, f 4-2 f is the focal length of the sub-lens of the fourth lens 74 that is closest to the fifth lens 75, which is also the focal length of the fourth sub-lens 742. 总 This represents the total focal length of the optical imaging lens group. It should be noted that the specific focal length values ​​for each lens are shown in Table 10:

[0182] Table 10 Focal length parameters of each lens in the optical imaging lens group

[0183]

[0184]

[0185] The refractive indices and dispersion coefficients of the first lens 71, the fourth sub-lens 742, and the sixth sub-lens 761 in the optical imaging lens group satisfy the following conditions:

[0186] The refractive index and dispersion coefficient of the first lens 71 are 1.78 and 21.4, respectively; the refractive index and dispersion coefficient of the fourth sub-lens 742 are 1.9 and 27.1, respectively; and the refractive index and dispersion coefficient of the sixth sub-lens 761 are 1.83 and 21.6, respectively.

[0187] In the optical imaging lens assembly provided in Embodiment 4 of the present invention, the total focal length of the optical imaging lens assembly is 2.58 mm, and the field of view is 28 degrees. The parameters of the radius of curvature, thickness, refractive index, and dispersion coefficient of each lens used for imaging the scanning surface 08 are shown in Table 11.

[0188] Table 11 Structural parameters of the optical imaging lens assembly in Example 4

[0189]

[0190] It should be noted that Tables 10 and 11 are detailed structural data of the optical imaging lens group in Embodiment 4. The units of radius of curvature, thickness and focal length are all in millimeters. Surfaces 0-20 in Table 11 represent the surfaces from the first side to the second side in sequence. An optical surface with an "infinite" radius of curvature in the imaging plane refers to a plane.

[0191] Furthermore, the conic coefficients and aspherical conic coefficients of the surfaces corresponding to the fifth lens 75 and the seventh lens 77 (both aspherical lenses) are shown in Table 12 below:

[0192] Table 12 Conicity and asphericity data for different lens surfaces in Example 4

[0193] Surface k A4 A6 A8 A10 A12 A14 A16 11 -9.69E-01 6.51E-02 3.83E-02 -2.30E-02 4.47E-02 -5.37E-02 2.70E-02 -4.99E-03 12 -1.81E+00 -2.00E-02 1.53E-02 -7.08E-03 7.45E-03 -3.20E-03 6.67E-04 -6.24E-05 16 -6.75E-01 5.42E-02 -2.09E-02 1.51E-03 4.48E-03 -2.00E-03 3.54E-04 -2.26E-05 17 -1.51E+00 2.09E-01 -1.20E-01 5.20E-02 1.77E-02 3.09E-04 -1.21E-02 3.86E-03

[0194] Table 12 shows the conic coefficient and aspheric coefficient data in Example 4, where k is the conic coefficient in the aspheric curve equation, and A4 to A16 represent the 4th to 16th order aspheric coefficients of each surface.

[0195] Additionally, please refer to the following: Figure 2b and Figure 15 In this embodiment, the maximum effective half-aperture Y1 of the third lens along the radial direction, the maximum effective half-aperture Y2 of the two opposite surfaces of the fourth and fifth lenses along the radial direction, and the maximum effective half-aperture Y3 of the seventh lens along the radial direction satisfy the following relationship: Y1 / Y2=1.31, Y3 / Y2=1.5.

[0196] Furthermore, tests showed that when the image light corresponding to the scanning surface is projected using the aforementioned optical imaging lens group, its optical transfer function curve is as follows: Figure 16 As shown, the field distortion curve is as follows: Figure 17 As shown, the vertical axis color difference curve is as follows: Figure 18 As shown; among them, the Modulation Transfer Function (MTF) curve represents the overall resolution level of an optical system, the Field Curve Distortion curve represents the F-Tan (theta) distortion magnitude (percentage) under different field angles, and the Vertical Chromatic Aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axial direction.

[0197] Depend on Figures 16-18 Observations show that the optical imaging lens group in Example 4 has good imaging resolution and small optical system distortion and chromatic aberration across the entire field of view. Therefore, the optical imaging lens group can clearly image the scanning surface image of the fiber optic scanner and has good imaging effect.

[0198] Of course, in practical applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element can be set on the second side of the optical imaging lens assembly, and the optical imaging lens assembly can be installed in the housing. This allows the curved image formed by the image source (such as a fiber optic scanner) to be imaged onto a flat carrier, thus achieving clear imaging.

[0199] Embodiment five

[0200] Figure 19This is a schematic diagram of an optical imaging lens assembly provided in an embodiment of the present invention. The optical imaging lens assembly includes a first side (i.e., Figure 19 From the side where aperture 09 is located (to the second side, that is, Figure 19 The first lens 91, the second lens 92, the third lens 93, the fourth lens 94, the fifth lens 95, the sixth lens 96, the seventh lens 97 and the eighth lens 98 are arranged sequentially along the common optical axis on the side where the scanning surface 10 is located.

[0201] In this embodiment, each pair of adjacent lenses in the first lens 91, second lens 92, third lens 93, fourth lens 94, fifth lens 95, sixth lens 96, seventh lens 97, and eighth lens 98 is spaced apart, and the first lens 91, second lens 92, third lens 93, fifth lens 95, seventh lens 97, and eighth lens 98 are six single non-bonded lenses. The fourth lens 94 is a cemented lens composed of two sub-lenses, with the two sub-lenses being fourth sub-lens 941 and fourth sub-lens 942 from the first side to the second side; the sixth lens 96 is also a cemented lens composed of two lenses, with the two sub-lenses being sixth sub-lens 961 and sixth sub-lens 962 from the first side to the second side.

[0202] The focal lengths of the first lens 91 to the eighth lens 98 from the first side to the second side are negative, positive, positive, positive, positive, positive, negative and positive, respectively. The fourth lens 94 includes the fourth sub-lens 941 and the fourth sub-lens 942, whose focal lengths are positive and negative, respectively. The sixth lens 96 includes the sixth sub-lens 961 and the sixth sub-lens 962, whose focal lengths are negative and positive, respectively.

[0203] Both the first and second side surfaces of the first lens 91 are concave near the optical axis;

[0204] Both the first and second side surfaces of the second lens 92 are convex.

[0205] The first side surface of the third lens 93 is concave near the optical axis, and the second side surface is convex.

[0206] The first and second side surfaces of the fourth sub-lens 941 in the fourth lens 94 are both convex surfaces, and the first and second side surfaces of the fourth sub-lens 942 are both concave surfaces.

[0207] The first side surface of the fifth lens 95 is concave near the optical axis, and the second side surface is convex near the optical axis;

[0208] In the sixth lens 96, the first and second side surfaces of the sixth sub-lens 961 are both concave, while the first and second side surfaces of the sixth sub-lens 962 are both convex.

[0209] The first side surface of the seventh lens 97 is convex near the optical axis, and the second side surface is concave near the optical axis;

[0210] The first side surface of the eighth lens 98 is convex, and the second side surface is concave near the optical axis.

[0211] In this embodiment, the focal lengths of the first lens 91 and the fourth lens 94 in the optical imaging lens group satisfy the following relationship:

[0212] 0.7≤|f1 / f 总 |≤1.2,0.8≤|f 4-2 / f 总 |≤1.5, where f1 is the focal length of the first lens, f 4-2 f is the focal length of the sub-lens of the fourth lens 94 that is closest to the fifth lens 95, which is also the focal length of the fourth sub-lens 942. 总 This represents the total focal length of the optical imaging lens group. It should be noted that the specific focal length values ​​for each lens are shown in Table 13:

[0213] Table 13 Focal length parameters of each lens in the optical imaging lens group

[0214] Lens Focal length Lens focal length / total lens focal length First lens 91 -2.83 -1.05 Second lens 92 4.74 1.75 Third lens 93 7.65 2.83 Fourth lens 94 22.83 8.45 Fourth sub-lens 941 4.10 1.52 Fourth sub-lens 942 -3.80 -1.41 Fifth lens 95 5.88 2.18 Sixth lens 96 23.76 8.80 Sixth sub-lens 961 -17.03 -6.31 Sixth sub-lens 962 11.75 4.35 Seventh lens 97 -9.32 -3.45 Eighth lens 98 6.34 2.35

[0215] The refractive indices and dispersion coefficients of the first lens 91, the fourth sub-lens 942, and the sixth sub-lens 961 in the optical imaging lens group satisfy the following conditions:

[0216] The refractive index and dispersion coefficient of the first lens 91 are 1.79 and 23, respectively; the refractive index and dispersion coefficient of the fourth sub-lens 942 are 1.72 and 24, respectively; and the refractive index and dispersion coefficient of the sixth sub-lens 961 are 1.77 and 21.8, respectively.

[0217] In the optical imaging lens assembly provided in Embodiment 5 of the present invention, the total focal length of the optical imaging lens assembly is 2.58 mm, and the field of view is 28 degrees. The parameters of the radius of curvature, thickness, refractive index, and dispersion coefficient of each lens used to image the scanning surface 10 are shown in Table 14.

[0218] Table 14 Structural parameters of the optical imaging lens assembly in Example 5

[0219]

[0220]

[0221] It should be noted that Tables 13 and 14 are detailed structural data of the optical imaging lens group in Embodiment 5. The units of radius of curvature, thickness and focal length are all millimeters. Surfaces 0-20 in Table 14 represent the surfaces from the first side to the second side in sequence. An optical surface with an "infinite" radius of curvature in the imaging plane refers to a plane.

[0222] Furthermore, the conicity and asphericity of the surfaces corresponding to the fifth lens 95 and the seventh lens 97 (both aspherical lenses) are shown in Table 15 below:

[0223] Table 15. Conicity and asphericity data of the aspherical lens surface in Example 5.

[0224] Surface k A4 A6 A8 A10 A12 A14 A16 11 -1.06E+00 8.34E-02 2.36E-02 -3.28E-02 5.08E-02 -5.02E-02 2.39E-02 -4.39E-03 12 -1.58E+00 -2.26E-02 1.38E-02 -8.06E-03 7.33E-03 -3.26E-03 7.23E-04 -6.72E-05 16 -5.11E-01 5.29E-02 -1.64E-02 -3.02E-04 4.32E-03 -1.84E-03 3.24E-04 -1.81E-05 17 -5.21E+00 1.35E-01 -7.26E-02 2.82E-02 -1.63E-03 2.82E-03 -3.58E-03 9.62E-04

[0225] Table 15 shows the conic coefficient and aspheric coefficient data in Example 5, where k is the conic coefficient in the aspheric curve equation, and A4 to A16 represent the 4th to 16th order aspheric coefficients of each surface.

[0226] Additionally, please refer to the following: Figure 2b and Figure 19 In this embodiment, the maximum effective half-aperture Y1 of the third lens along the radial direction, the maximum effective half-aperture Y2 of the two opposite surfaces of the fourth and fifth lenses along the radial direction, and the maximum effective half-aperture Y3 of the seventh lens along the radial direction satisfy the following relationship: Y1 / Y2=1.36, Y3 / Y2=1.41.

[0227] Furthermore, tests showed that when the image light corresponding to the scanning surface is projected using the aforementioned optical imaging lens group, its optical transfer function curve is as follows: Figure 20 As shown, the field distortion curve is as follows: Figure 21 As shown, the vertical axis color difference curve is as follows: Figure 22 As shown; among them, the Modulation Transfer Function (MTF) curve represents the overall resolution level of an optical system, the Field Curve Distortion curve represents the F-Tan (theta) distortion magnitude (percentage) under different field angles, and the Vertical Chromatic Aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axial direction.

[0228] Depend on Figures 20-22 Observations show that the optical imaging lens group in Example 5 has good imaging resolution and small optical system distortion and chromatic aberration across the entire field of view. Therefore, the optical imaging lens group can clearly image the scanning surface image of the fiber optic scanner and has good imaging effect.

[0229] Of course, in practical applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element can be set on the second side of the optical imaging lens assembly, and the optical imaging lens assembly can be installed in the housing. This allows the curved image formed by the image source (such as a fiber optic scanner) to be imaged onto a flat carrier, thus achieving clear imaging.

[0230] Scanning display device

[0231] The aforementioned optical imaging lens assembly can be used in conjunction with a fiber optic scanner (or a corresponding fiber optic scanning module) to constitute the scanning display device in the embodiments of this application (e.g., Figure 1a , 1b As shown, the optical imaging lens group is positioned on the output optical path of the fiber optic scanner. The first side of the optical imaging lens group faces the scanning output direction of the fiber optic scanner. Preferably, the optical imaging lens group is coaxial with the central optical axis of the fiber optic scanner. Of course, the structure and general principle of the fiber optic scanner can be found in the aforementioned... Figure 1a , 1b The corresponding content will not be elaborated on here.

[0232] Near-eye display device

[0233] In this application, the scanning display device can be further applied to a near-eye display device, and can be used in conjunction with a near-eye display module to form the near-eye display device in the embodiments of this application, for use as a head-mounted AR device (such as AR glasses). The scanning display device is disposed in the near-eye display module.

[0234] The near-eye display module may include: a light source, processing and control circuitry, a wearable frame structure, and a waveguide. The image beam output from the light source enters the scanning display device, where it is scanned by a fiber optic scanner and output to the optical display lens assembly. The scanning surface of the fiber optic scanner (see reference) Figure 3 The scan surface 02 and its corresponding Figure 2a The scanning surface 230 in the image is converted into an imaging plane after passing through the optical display lens group (see reference). Figure 2a The imaging plane 240 in the waveguide is coupled into the waveguide as the entrance pupil surface, and then coupled out through the waveguide to enter the human eye.

[0235] As another possible implementation, the scanning display device can be further combined with the near-eye display module to form the near-eye display device in the embodiments of this application, and used as a head-mounted VR device (such as a VR helmet / glasses). The scanning display device is disposed in the near-eye display module.

[0236] In this embodiment, by rationally optimizing the focal length of the five coaxial lenses in the optical imaging lens group, the optical power of the system can be reasonably dispersed, the aberrations generated by the lenses can be reduced, and the purpose of correcting various aberrations can be achieved. While improving the field of view, clear imaging of the image surface is achieved. By limiting and optimizing the refractive index, dispersion coefficient, and surface structure of the five coaxial lenses, the imaging quality and field of view are further improved. By limiting and optimizing the design of the five coaxial lenses into aspherical surface structures, the overall structure of the optical imaging lens group is more compact while further improving the imaging quality, thus meeting the production requirements for miniaturization of lens products.

[0237] The above descriptions are merely preferred embodiments of this application. Each embodiment is only used to illustrate the technical solution of this application and is not intended to limit this application. Any technical solution that can be obtained by those skilled in the art through logical analysis, reasoning, or effective experiments based on the concept of this application should be within the scope of this application.

[0238] The various embodiments in this application are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0239] The terms "first," "second," "first," or "second" as used in the various embodiments of this disclosure may modify various components regardless of their order and / or importance, but these terms do not limit the corresponding components. The above terms are configured only for the purpose of distinguishing an element from other elements. For example, a first lens and a second lens represent different lenses, although both are lenses.

Claims

1. An optical imaging lens assembly, characterized in that, The first side of the optical imaging lens group corresponds to a planar image, and the second side of the optical imaging lens group corresponds to a curved image. The curved image is an arc-shaped scanning surface scanned by a fiber optic scanner or emitted by other image sources. The optical imaging lens group consists of a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged coaxially from the first side to the second side. The focal lengths of the first lens, the second lens, the third lens, and the sixth lens are negative, positive, positive, and positive, respectively. The first lens and the optical imaging lens group have the following relationship: 0.7 ≤ |f1 / f 总 |≤1.2, where f1 is the focal length of the first lens, and f 总 The total focal length of the optical imaging lens group; Both the fourth lens and the sixth lens are spherical cemented lenses, and both the fourth lens and the sixth lens include two sub-lenses. The two sub-lenses of the fourth lens are arranged along the same optical axis from the first side to the second side, and their corresponding focal lengths are positive and negative, respectively. The two sub-lenses of the sixth lens are arranged along the same optical axis from the first side to the second side, and their corresponding focal lengths are negative and positive, respectively.

2. The optical imaging lens assembly according to claim 1, characterized in that, The first lens, the second lens, the third lens, the fourth lens, the sixth lens, and the eighth lens are all spherical lenses; Both the fifth lens and the seventh lens are aspherical lenses.

3. The optical imaging lens assembly according to claim 2, characterized in that, The second side surface of the fourth lens, which is close to the sub-lens of the fifth lens, is concave; the first side surface of the fifth lens is concave.

4. The optical imaging lens assembly according to claim 2, characterized in that, The focal lengths of the fourth lens, the fifth lens, the seventh lens, and the eighth lens are negative, positive, positive, and positive, respectively. The sub-lens of the fourth lens closest to the fifth lens has the following relationship with the optical imaging lens group: 0.8 ≤ |f 4-2 / f 总 |≤1.5, where f 4-2 The focal length of the sub-lens of the fourth lens closest to the fifth lens, f 总 The total focal length of the optical imaging lens group is given.

5. The optical imaging lens assembly according to claim 2, characterized in that, The maximum effective half-aperture of the third lens along the radial direction is Y1, the maximum effective half-aperture of the two opposite surfaces of the fourth and fifth lenses along the radial direction is the same and is Y2, and the maximum effective half-aperture of the seventh lens along the radial direction is Y3. Wherein, Y1 and Y2 have the following relationship: 1≤Y1 / Y2≤1.4; The following relationship exists between Y2 and Y3: 1.4 ≤ Y3 / Y2 ≤ 1.

7.

6. A scanning display device, characterized in that, The invention includes a fiber optic scanner and an optical imaging lens group according to any one of claims 1 to 5, wherein the fiber optic scanner is used to scan and emit light to display an image, and the optical imaging lens group is used to magnify and project the scanning surface corresponding to the light emitted by the fiber optic scanner. The fiber optic scanner includes an actuator and an optical fiber fixed to the actuator. The portion of the optical fiber extending beyond the actuator forms an optical fiber cantilever, which performs two-dimensional scanning under the drive of the actuator.

7. A near-eye display device, characterized in that, The near-eye display device is used as a head-mounted augmented reality device, and includes at least a near-eye display module and a scanning display device according to claim 6, wherein the scanning display device is disposed in the near-eye display module.

8. A near-eye display device, characterized in that, The near-eye display device is used as a head-mounted virtual reality device, and includes at least a near-eye display module and a scanning display device according to claim 6, wherein the scanning display device is disposed in the near-eye display module.

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